The present invention relates in general to an automatically actuated backup power circuit for at least partially energizing a multi-power requirement load upon loss of or malfunction of its primary power source.
More particularly, the present invention is directed to a battery pack containing standby emergency power supply adapted to partially energize a hydraulic elevator control panel experiencing a malfunction in its normal power supply wherein lowering of the elevator car and opening of the car doors are effected to permit safe egress of passengers therefrom.
Such standby emergency power supplies are known in the art, as illustrated by U.S. Pat. Nos. 3,532,186; 3,706,357; and 3,902,573. These known circuits, being complex, costly, and of a generally electromechanical nature with inherent reliability problems, have not, to the best of the present inventor's knowledge, met with commercial success.